Reciprocable actuator device



Feb. 24, 1959 s. WEISER 2,874,913

RECIFROCABLE ACTUATOR DEVICE Filed Oct. 18, 1955 2 Sheets-Sheet lINVENTOR: SIDNEY WEI SEE,

Feb. 24, 1959 Filed Oct. 18, 1955 S. WEISER RECIPROCABLE ACTUATOR DEVICE2 Sheets-Sheet 2 INVENTOR: smNEy weusaa,

Hi5 AE/WI RECIPRO'CABLE ACTUATOR DEVICE Sidney Weiser, Plainview, N. Y.,assignor to Federal Manufacturing & Engineering Corporation, acorporation of New York Application October 18, 1955, Serial No. 541,129r i 8 Claims. (Cl. 242-55) The invention relates to actuator devices,and relates more particularly to such devices that can actuate areciprocable linear movement.

The invention has among its objects to provide such adevice that willwork with a minimum power requirement for a given load, and which willbe powered throughout the entire path in either direction, and willarrest the movement at the end of the path in either direction freeUnited States Patent Further objects and advantages of the inventionwill be set forth in part in the following specification and in partwill be obvious therefrom without being specifically referred to, thesame being realized. and attained as pointed out in the claims hereof. tI In the accompanying drawings. 1 i t i Fig. 1 is a schematic sideelevational view of the device in accordance with the invention appliedto a slide changer in a photographic projector;

Fig. 2 is a front elevational view of thedevice, with the cover removed,partly in section; and

Fig. 3 is an under-side plan view, as seen in direction 3 3 of Fig. l,but with the cover still removed. In carrying the invention into effectin one of the embodiments which has been selected for illustration inthe accompanying drawings and for description in this specification, andreferring now particularlyto Fig. l, the actuator device 11 is appliedto the shifting part 12 of a slide changer 13 that isinstal'led on aphotographic projector 14. i i t In view of the exemplified applicationto a slide changer referred to, the device 11 is shown suspended withthe base plate 16 on top and the removable cover or housing 17 disposedbelow the plate 16. It will, of course, be obvious to those skilled inthe art that the device 11 can also be mounted in any other manner forother uses. t

The base plate 16 may be placed below the under-side .of the shiftablepart 12 by well-known conventional means, for instance by means of abracket 18 that is connectedto the base plate 16 and which is removablysecured to the frame of the slide changer 13. On the shift- -in'g part12 there may be mounted a. pin 19 that is received in a reciprocatingelement of the actuatordevice, for instancelan elongated slider. 21 thatprojects from the plate 16 and .Which has a recess 22 that engages thepin 1 2,374,913 Patented Feb. 24, 1959 shifting part 12 is movablebetween a projecting position (shown in solid lines in Fig. 1) whereinit holds a slide in register with the optical axis of the projector 14and, respectively, a retracted position (shown in broken lines inFig. 1) wherein it returns the slide into the slide changer 13.

As best shown in Fig. 2, the slider 21 protrudes through an elongatedslot 23 of the base, plate 16. The opposite ends 24 and '26 of the slot23 define the limits of the path of the slider 21.

The slider 21 is'secured to a reciprocably movable member, such as aflexible band or tape 27, that is suspended between and connected torotatable driving ele ments, such as a first reeling drum 28 and asecond reeling drum 29. There is also provided an idler drum 31, and theflexible tape 27 is suspended substantially straight between the idlerdrum 31 and the second reelingdrum 29. The ends of the tape 27 areconnected to the reeling drums 28 and 29, respectively.

The first reeling drum 28 is freely rotatably journalled on a rod 32that is supported with relation from the plate 16, for instance by meansof brackets 33. The drum 28 has a restricted portion on the externalsurface of which there is journalled freely rotatably a rotor, such as agear Wheel 34. To the drum 28 there is screwed, frontwardly of the wheelgear 34, a cam disc 36 that has a detent 37. On the front face of thegear wheel 34 there is pivoted about a pin 38 a latching member or latch39 that has a long arm 41', and a short arm 42 that forms an angle withthe long arm41. The short arm 42 is so positioned and dimensioned thatit can engage the detent 37 for coupling the gear wheel 34 with the cam.disc 36 of the drum 28. A tension spring 43 has one end connected to thegear wheel 34 and the other end to the latch 39, and

urges the latch 39 to turn in a direction D, tending to disengage theshort arm 42 from the detent 37.

The long arm 41 carries near its free end a Weight 44, and has anextension 46 that projects frontwardly of the face of the gear wheel 34.

A pinion 47 is freely turnably mounted on a sourceof rotary power, suchas a shaft 48 of an electric motor 49. The pinion 74 meshes with thegear 34. 7 An elastic frictional slip clutch or friction clutch 51 isprovided between the motor shaft 48 and the pinion 47. It comprises ahelical compression spring 52 that bears: with one end against the frontsurface of a disc 53 that is secured to the shaft 48, and the spring52bears with its other end against the rear surface 54 of the pinion 47.

The motor 49 is so arranged that upon energization it will turn theshaft in the direction D. When the motor 49 is energized, the frictionclutch 51 will couple. the pinion 47 to turnwith the shaft 48 in thedirection D, and the pinion 47 will turn the gear wheel 34 in thedirection C. Upon the attainment of a predetermined angular velocity,the centrifugal power will force the weight 44 outwardly, and cause thelatch 39 to turn about the pivot 38 in the direction C, so that theshort arm 42 will engage the detent 37, thereby coupling the gear Wheel34 to the drum 28 to turn the drum 28 in the direction C. The tape 27will thereby be reeled-in by the drum 28, and will move the slider 21 inthe direction A.

{The engaging surfaces of the short arm 42 and the detent 37 are soarranged, relative to the position of the pin 38 and the axis of the camdisc 36, that they can be disengaged only upon the application of aforce in excess of that of the spring 43, and will thus normally remainengaged.

To return the slider 21 in the direction B, the tape 27 will be reeledby the second reeling drum 29. The drum 29 is journalled for freerotation on a rod 56 that is supported on brackets 57 with relation tothe plate 16.

A helical spring 58, for instance made ofmusicfwire,

has one of its ends connected to a support 57 and the other end to thedrum 29.

When the tape 27 is moved by the first drum 28 in the direction A, itwill turn the drum 29 in the'direction C. By this rotation of the drum29, the spring 58 wil be tensioned, and energy will be stored therein.When the motor 49 is de-energized, and thereby the motor driving appliedto the first drum 28 ceases, the spring 58 will apply its stored energyto the second drum 29, and the drum 29 will turn in the direction D andwill reel-in the tape 27 causing a movement of the slider 21 in thedirection B. During the movement of the slider 21 in the direction B,the tape will rotate the first drum 28 in the direction D, and the camdisc36 will turn the gear wheel 34 in the direction D, owing to thecontinued engagement of the detent 37 with the latch 39.

In order to release the latching engagement there is provided a releasemechanism 61, which includes an arm 62. V The arm 62 is so supportednear the face of the gear wheel 34, that it will project into the paththat the extension 46 describes when the latch 39 engages the detent 37.The arm 62 has an arcuate slot 63 through which there protrudes astationary pin 64. Adjacent one of the long edges 66 of the arm 62,there abuts a stationary bar 67. A spring 68 urges the arm 62 into theposition shown in Fig. 2.

When the latch 39 engages the detent 37 while the gear wheel 34 rotatesin the direction C under the impulse of the motor 49, the extension 46of the latch 39 will strike the arm 62 from below. Owing to the slot 63,the abutment bar 67, and the spring 68, however, the arm 62 will bepushed by the extension 46 into a position (shown in broken lines inFig. 2) wherein the arm 62 clears the path of the extension 46.

When, on the other hand, the gear wheel 34 is turned by the drum 28 inthe direction D under the impulse of the spring 58, the impact betweenthe extension 46 4 stroke, yet free from any rebound at the end of thestroke.

The arrangement hereabove described in operation is sufficiently strongto carry the slider 21 with the shiftable part 12 throughout the path inthe direction A. The

friction clutch 51 will prevent any rebound upon impact of the slider 21with the edge 24, as in that instant the pinion 47 will slip on theshaft 48.

While the switch 69 remains closed, the slider 21 will remain in the endposition of abutment with the edge 24, as the friction clutch 51 tendsto turn the pinion 47 in the direction in which it caused the movementof the a slider 21 in the direction A.

During the movement of the slider 21 in the direction A, the tape 27 hasrotated the second drum 29 in the direction C, thereby storing energy inthe spring 58. Upon opening of the switch 69, the motor will stop, andthereby the force tending to turn the gear wheel 34 in the direction Cwill cease. Thereupon, the spring 58 will turn the second drum 29 in thedirection D. During the beginning of the winding of the tape 27 onto thedrum 29, under the impulse of the spring 58, the tape will turn in thedirection D not only the first drum 28 but also the gear wheel 34 thatis latched thereto and the pinion 47 that meshes with the wheel 34. Thegear 34 turns the pinion 47 which owing to the strong force of thespring 52 turns, the shaft 48 in the opposite direction than whenenergized electrically. During this movement, the slider 21 Will beshifted in the direction B.

When the slider 21 has completed about one-half of the length of thereturn path, the extension 46 of the latch 39 will strike the arm 62 atthe edge 65 causing the latch 39 to be turned about the pin 38 indirection D and the arm 62 will cause the unlatching of the latch '39.When the gear wheel turns in the direction D,

the extension 46 will strike the inner edge 65. of the arm 62, and thearrangement of the pin 64 and of the abutment bar 67 prevents anyyielding of the arm 62. Instead, the latch 39 will yield and will turnabout the pivot 38, disengaging the arm 41 from the detent 37 therebycausing uncoupling of the drum 28 from the gear wheel 34. V

The motor 49 is connected to an electric source, indicated schematicallyby a battery 70, in a circuit which includes an operating switch 69.

Operation The operation of the above described apparatus is as follows.

When the switch 69 is closed, the motor shaft 48 will revolve in thedirection D. The friction clutch 51 will cause the pinion 47 to rotatewith the shaft 48, thereby causing rotation of the gear wheel 34 in thedirection C.

When a predetermined angular speed has been attained by the gear wheel34, the weight 44 will cause the latch 39 to swing about the pin 38, andthe arm 42 will engage 'the detent 37, coupling the gear wheel 34 withthe cam disc 36 and thereby with the first reeling drum 28. Rotation ofthe reeling drum in the direction C will wind up the tape '27 onto thedrum 28, causing movement of the portion ofthe tape 27 in the directionA. This movement of the tape 27 causes shifting of the slider 21 a inthe direction A, thereby moving the shiftable part 12 of the exemplifiedslide changer 13 in the direction A.

The movement of the slider 21 in the direction A ceases upon impact ofthe slider 21 with the edge v24 of the slot 23. At that instant, theshiftable part 12 of the slide changer 13 will be in the slideprojecting position shown in solid lines in Fig. 1.

Slide changers of this type require that the 'full shifting force beapplied substantially throughout the entire resulting in disengagementof the arm 42 from the detent 37. Thereby, the latch 39 is unlatched,and the gear 34 uncoupled from the first drum 28.

During the remainder of the movement of the slider 21 in the directionB, the tape 27 will pull only the drum 28, while the gear 34 and thepinion 47 will be coast ing freely in the direction opposite to thatwhen electrically energized. The movement of the slider 21 in thedirection B will continue until the slider 21 strikes the opposite edge26 of the slot 23. The spring 58 is strong enough to prevent anyrebound, and to pull the load of the shiftable part 12 to the workingposition wherein the slide is positioned in registry with the opticalaxis of the projector (shown in solid lines in Fig. 1).

The arrangements of the friction clutch 51 and of the latch 39 olierseveral advantages. They permit the use of a comparatively weak motor49, as the drum 28 will be engaged only after a suflicient amount ofrotary energy has been stored in the gear wheel 34, which energy isreflected by the centrifugal force that is applied to the weight 44 ofthe latch 39. The friction clutch .51

renders possible not only the abutment of the slider 21 against the edge24 free from any rebound, but also permits the slider 21 to come to restin that abutment position adjacent the edge 24 while the motor 49 isrunning or stalling.

The motor 49 is merely strong enough to overcome the load of theshiftable part 12 and the force .of the spring 58.

During the return trip of the slider 21, the energy that has been storedin the spring 58 is utilized. While springs have a force characteristicthat decreases rapidly with decreasing deflection, the movement of theshiftable part 12 requires a pulling force that does not diminish to.-wa rd's'the end. The arrangement of the latch 39 accomplishes this byreducing the load that the spring 58 needs to pull during the secondhalf of the path of the slider 21, by uncoupling the drum 28 from thegear wheel 34 and pinion 47. a

To operate the device, the operator will first close the switch 69 formovement of the slider 21 and theretofore of the shiftable part '1-2 inthe direction A. By this movement, a color slide is moved out from aposition 'of registry with the optical axis of the projector 14. Whilethe switch 69 remains closed, the color slide will be retracted. Uponopening of the switch 69, the slide 21 will be moved in the direction Binto the optical projector axis.

For the exemplified use, it is important that the shifting takes placefree from any rebound, as any rebound would move the color slideout-of-registry with either the optical axis of the projector 14 or theaxis of the slide changer 13. The construction described in theforegoing prevents rebound in either end position of the slider 21.

I wish it to be understood that I do not desire to be limited to theexact details of construction shown and described, for obviousmodifications will occur to a person skilled in the art.

Having thus described the invention, what I claim as new and desire tobe secured by Letters Patent, is as follows: t V

1. In a reciprocable actuator device, in combination, a first reelingdrum, a second reeling drum, and an idler drum, a flexible membersuspended between said drums and being connected to said reeling drumsand moving between said second reeling drum and said idler drum in asubstantially straight path, said reeling drums being operable toreciprocate said member, said first reeling drum being freely journalledfor rotation, a motor, control means between said motor and said firstreeling drum operable for releasably coupling the motor therewith tomove said member in one direction, said second drum being journalledfreely turnably about an axis parallel to the axis of said first reelingdrum and including a spring tensionable when said second reeling drum ismoved by said member under the power of said motor, said spring beingoperable to return said member in an opposite direction uponde-energization of said motor, and means operable for releasing saidcontrol means to disengage said first reeling drum from said motorduring the 'return movement of said member to reduce the driving load ofsaid spring.

2. In a reciprocable actuator device, as claimed in claim 1, togetherwith, an element connected to said member between said idler drum andsaid second reeling drum, whereby said element will be reciprocated in asubstantially straight path as the motor is energized and de-energized,and stop means operable to limit the path of said element and therebythe movement of said member in either direction.

3. In a reciprocable actuator device, as claimed in claim 2, saidcontrol means comprising a shaft on said motor, a pinion journalled onsaid shaft, a gear wheel meshing with said pinion and journalledcoaxially with said first reeling drum, centrifugally operative latchingmechanism between said gear wheel and said first ree1- ing drum operableto couple releasably said gear wheel with said first reeling drum uponthe attainment of a predetermined angular velocity of said gear wheelwhen said gear wheel is driven from said motor, said latching mechanismbeing releasable when said gear wheel is driven from said second reelingdrum, friction means between said motor shaft and said pinion, saidmotor and said friction means and said spring said gear wheel being sodimensioned that said element on said member will be arrested by saidpath limiting means in eitherdirection freefrom rebound when saidelement of said flexible member is applied to a load for movementthereof in both directions.

4. In a reciprocable actuator device, in combination, a reciprocablymovable member, and means for reciprocating said member comprising arotatable first driving element connected to said member and operable tomove it in one direction, a second rotatable driving element connectedto said member and actuatable to return said member in an oppositedirection, a motor, control means including a slip clutch between saidmotor and said first driving element operable for releasably connectingsaid first driving element with said motor upon energization of saidmotor, said second driving element including resilient means and beingoperable for tensioning said resilient means when driven by said memberas, said member is moved in said one direction from said first drivingelement, said resilient means, upon de-energization of said motor,driving said second driving element in an opposite direction to returnsaid member, the

power of said resilient means being inferior to the power delivered bysaid first driving element when driven from said motor, whereby uponenergizationof said motor said member will beactuated in one directionagainst the force of said resilient means and, respectively, upondeenergization of said motor said member will be moved in the oppositedirection by said resilient means, said motor including acshaft, saidcontrol means comprising a rotor in driven connection with saidmotor'shaft and driven therebyin one direction when said motor isenergized, latching means actuatable centrifugally for latching saidrotor with saidfirst driven element upon the attainment of apredetermined angular velocity by said rotor to drive said first drivingelement from said rotor, and release means stationary with respecttosaid rotor and operable to engage said latching means to release itthereby unlatching said first driving element from said rotor touncouple said first driving element from said motor during rotation ofsaid rotor in an opposite direction following de-energization of themotor.

5. In a reciprocable actuator device, as claimed in claim 4, saidlatching means comprising a lever pivoted to said rotor and including aweight and having a finger and an extension, a detent connected to saidfirst driving element, said finger being operable to engage said detentupon the application of centrifugal force of a predetermined magnitudeon said weight, said release means including a resiliently suspended armprojecting into the path of said extension as it rotates with the rotoraround the axis thereof and being operable to yield upon impact by saidextension during rotation of said rotor in one direction and,respectively, to engage said extension during rotation of said rotor inthe opposite direction thereby disengaging said finger from said detentreleasing the driving connection between said rotor and said firstdriving element.

6. In a reciprocable actuator device, having a source of rotary power,in combination, a reciprocably movable member, means for oppositelydriving said member comprising two rotatable elements spaced from eachother and each in driving connection with said member, means for drivingone of said elements including a control mechanism operable to connectsaid one element to said source frictionally for driving said member inone direction and, respectively, for disconnecting it from said sourceduring driving of said member in an opposite direction, the otherelement including resilient means operable to be tensioned by saidmember when it is moved in said one direction and, respectively, todrive said member in the opposite direction upon cessation ofapplication of said source energy, and means for energizing andde-energizing said source, said control means comprising a wheeljournalled coaxially with said one element and driven from said source,centrifugally actuatable latching means including a weighted latchpivoted to said wheel and a detent formed on said one element, saidlatch being operable to engage said detent upon the attainment of apredetermined angular velocity of said wheel in a direction whereby uponlatching said one element will drive said one member in said onedirection, and means operable for releasing said latch including arelease member operable to be engaged by said latch during rotation ofsaid wheel in either direction and to yield upon impact 7" by said latchwhen said wheel turns in the direction driving said member, and to abutwith said latch when said wheel turns in the opposite direction drivenby said member thereby forcing said latch out-of-engagement with saiddetent.

7. In a reciprocable actuator device, having a source of rotary power,in combination, a reciprocably movable member, means for oppositelydriving said member comprising two rotatable elements spaced fro-m eachother and each in driving connection with said member, means for drivingone of said elements including a control mechanism operable to connectsaid one element to said source friction'ally for driving said member inone direction and, respectively, for disconnecting it from said sourceduring driving of said member in an opposite direction, the otherelement including resilient means operable to be ten'sioned by said-member when it is moved in said one direction and, respectively, todrive said member in the opposite direction upon cessation ofapplication of said source energy, and means for energizing andde-cnergizing said source, said source including a shaft, a motorrotating said shaft in onedirection, said control means comprising apinion journalled on said shaft, a gear wheel driven by said pinion,friction generating means between said shaft and said pinion sufficientfor coupling said pinion with said shaft when said shaft turns in saidone direction, said pinion slipping on said shaft when rotated duringshaft'standstill and when braked during shaft rotation, andcentrifugally operable latching means between said gear wheel and saidoneelement operable to interconnect the same releasably during rotationof said gear wheel beyond a predetermined angular velocity in adirection whereby upon coupling said one element will move said memberin said one di rection.

8. In a reciprocable actuator device, as claimed in claim 7, togetherwith, said gear wheel being journalled coaxially with said one element,means operable for re! leasing said latch during rotation of said gearwheel in an opposite direction, whereby when said one element is drivenby said member from'the power of said resilient means it will beuncoupledfrom said gear wheel to reduce the driving load of saidresilient means.

R er nce -C;. ed n he fi e of h p e UNITED STATES PATENTS ,215,46 HerzigSept. 24, 1949 2,690,697 Rocca Oct. 5, 1954 FOREIGN PATENTS 466,118France Feb. 21, 1914

